#pragma ident "$Id$"

//============================================================================
//
//  This file is part of GPSTk, the GPS Toolkit.
//
//  The GPSTk is free software; you can redistribute it and/or modify
//  it under the terms of the GNU Lesser General Public License as published
//  by the Free Software Foundation; either version 2.1 of the License, or
//  any later version.
//
//  The GPSTk is distributed in the hope that it will be useful,
//  but WITHOUT ANY WARRANTY; without even the implied warranty of
//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
//  GNU Lesser General Public License for more details.
//
//  You should have received a copy of the GNU Lesser General Public
//  License along with GPSTk; if not, write to the Free Software Foundation,
//  Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110, USA
//
//  Copyright 2004, The University of Texas at Austin
//
//============================================================================
//============================================================================
//
//This software developed by Applied Research Laboratories at the University of
//Texas at Austin, under contract to an agency or agencies within the U.S.
//Department of Defense. The U.S. Government retains all rights to use,
//duplicate, distribute, disclose, or release this software.
//
//Pursuant to DoD Directive 523024
//
// DISTRIBUTION STATEMENT A: This software has been approved for public
//                           release, distribution is unlimited.
//
//=============================================================================

/**
 * @file GPSAlmanacStore.hpp
 * Store GPS almanac information (i.e. like the data in subframes 4&5) and
 * compute satellite Xvt based upon this data and the algorithms defined
 * in the IS-GPS-200.
 */

#ifndef GPSTK_GPSALMANACSTORE_HPP
#define GPSTK_GPSALMANACSTORE_HPP

#include <iostream>
#include <string>
#include <map>

#include "XvtStore.hpp"
#include "SatID.hpp"
#include "AlmOrbit.hpp"
#include "EngAlmanac.hpp"
#include "OrbElemStore.hpp"

namespace gpstk
{
/** @defgroup ephemstore */
//@{

/// Store GPS almanac information (i.e. like the data in subframes 4&5) and
/// compute satellite Xvt based upon this data and the algorithms defined
/// in the IS-GPS-200.
class GPSAlmanacStore : public OrbElemStore
{
public:

    GPSAlmanacStore()
    throw()
        : initialTime(CommonTime::END_OF_TIME),
          finalTime(CommonTime::BEGINNING_OF_TIME)
    {}

    virtual ~GPSAlmanacStore()
    {}

    /// Returns the position, velocity, and clock offset of the indicated
    /// object in ECEF coordinates (meters) at the indicated time.
    /// @param[in] id the object's identifier
    /// @param[in] t the time to look up
    /// @return the Xvt of the object at the indicated time
    /// @throw InvalidRequest If the request can not be completed for any
    ///    reason, this is thrown. The text may have additional
    ///    information as to why the request failed.
    virtual Xvt getXvt(const SatID& id, const CommonTime& t)
    const throw( gpstk::InvalidRequest );


    /// Returns the position, velocity, and clock offset of the indicated
    /// object in ECEF coordinates (meters) at the indicated time.
    /// It differs from getXvt in that it uses a different search
    /// algorithm - It will use the most recently received almanac
    /// information, thereby imitating what a receiver would be doing
    /// in real-time.  If there is no almanac data for that object prior
    /// to the requested time, InvalidRequest will be thrown.
    /// @param[in] id the object's identifier
    /// @param[in] t the time to look up
    /// @return the Xvt of the object at the indicated time
    /// @throw InvalidRequest If the request can not be completed for any
    ///    reason, this is thrown.  The text may have additional
    ///    information as to why the request failed.
    virtual Xvt getXvtMostRecentXmit(const SatID id, const CommonTime& t)
    const throw( gpstk::InvalidRequest );


    /// A debugging function that outputs in human readable form,
    /// all data stored in this object.
    /// @param[in] s the stream to receive the output; defaults to cout
    /// @param[in] detail the level of detail to provide
    virtual void dump(std::ostream& s = std::cout, short detail = 0)
    const throw();


    /// Edit the dataset, removing data outside the indicated time interval
    /// @param[in] tmin defines the beginning of the time interval
    /// @param[in] tmax defines the end of the time interval
    virtual void edit(const CommonTime& tmin,
                      const CommonTime& tmax = CommonTime::END_OF_TIME)
    throw();

    /// Clear the dataset, meaning remove all data
    virtual void clear(void) throw()
    {
        uba.clear();
    }

    /// Return time system (NB assumed always to be GPS)
    virtual TimeSystem getTimeSystem(void) const throw()
    {
        return TimeSystem::GPS;
    }

    /// Determine the earliest time for which this object can successfully
    /// determine the Xvt for any object.
    /// @return The initial time
    /// @throw InvalidRequest This is thrown if the object has no data.
    virtual CommonTime getInitialTime()
    const throw()
    {
        return initialTime;
    }


    /// Determine the latest time for which this object can successfully
    /// determine the Xvt for any object.
    /// @return The final time
    /// @throw InvalidRequest This is thrown if the object has no data.
    virtual CommonTime getFinalTime()
    const throw()
    {
        return finalTime;
    }

    virtual bool velocityIsPresent()
    const throw()
    {
        return true;
    }

    /// Return true if velocity data is present in the store
    virtual bool hasVelocity() const throw()
    {
        return true;
    }

    /// Return true if the given SatID is present in the store
    virtual bool isPresent(const SatID& sat) const throw()
    {
        if(uba.find(sat) == uba.end())
            return false;
        return true;
    }

    //---------------------------------------------------------------
    // Below are interfaces that are unique to this class (i.e. not
    // in the parent class)
    //---------------------------------------------------------------

    /// Returns the health of an SV for a particular time
    /// @param sat the satellite's SatID
    /// @param t the time to look up
    /// @return the SV health bits
    /// @throw InvalidRequest no data found in store
    short getSatHealth(const SatID sat, const CommonTime& t)
    const throw( gpstk::InvalidRequest);

    bool addAlmanac(const AlmOrbit& alm) throw();

    bool addAlmanac(const EngAlmanac& alm) throw();

    /// gets the closest almanac for the given time and satellite id,
    /// closest being in the past or future and "closest" being defined
    /// in terms of almanc time of epoch.
    /// @param sat the satellite's SatID
    /// @param t the time of interest
    AlmOrbit findAlmanac(const SatID sat, const CommonTime& t)
    const throw( gpstk::InvalidRequest );

    /// gets the most recent almanac for the given time and satellite id,
    /// most recent meaning it must have a transmit time before
    /// the specified time.
    /// @param sat the satellite's SatID
    /// @param t the time of interest
    AlmOrbit findMostRecentAlmanac(const SatID sat, const CommonTime& t)
    const throw( gpstk::InvalidRequest );

    /// returns all almanacs closest to t for all satellites
    AlmOrbits findAlmanacs(const CommonTime& t)
    const throw( gpstk::InvalidRequest );

protected:
    /// This is intended to just store weekly sets of unique EngAlmanacs
    /// for a single SV.  The key is ToA
    typedef std::map<CommonTime, AlmOrbit> EngAlmMap;

    /// This is intended to hold all unique EngEphemerises for each SV
    /// The key is the SatID of the SV.
    typedef std::map<SatID, EngAlmMap> UBAMap;

    /// The map where all EngAlmanacs are stored.
    UBAMap uba;

    CommonTime initialTime; //< Earliest Toa minus a half week
    CommonTime finalTime;   //< Last Toa plus a half week

};

//@}
}
#endif
